DESCRIPTION:
Following cancellation of the B-70 Valkyrie program, the US Air Force
began searching for a new design to replace the aging B-52. The result was the
B-1 program that dates as far back as 1965. Four prototypes of the B-1A were built as high speed, high
altitude bombers carrying a load of nuclear bombs. As the prototypes began flight testing, however, the
program was cancelled by President Carter in 1977. The Reagan Administration later renewed the B-1 program
in 1981 resulting in the significantly modified B-1B Lancer.

The B-1B design includes variable-geometry wings and is designed to evade enemy radar by flying low
altitude at near-sonic or supersonic speeds. The B-1 was one of the first aircraft designed with serious
thought and effort put into its stealth characteristics. With its buried engines, curved body, and
radar-absorbant materials, the B-1B has a radar cross-section less than 1/100th that of the B-52.

The B-1B was originally built as a nuclear-armed replacement for the B-52. In this capacity, the plane's
three bomb bays were compatible with SRAM and ALCM nuclear missiles as well as free-fall nuclear bombs.
Under the terms of the Stategic Arms Reduction Treaty (START) between the US and Russia, however, the B-1B
is no longer capable of delivering nuclear weapons. The Lancer has instead been re-equipped as a
conventional bomber to operate alongside the B-52H Stratofortress.

Compatibility with a wide array of conventional missiles and bombs has been developed under the
Conventional Mission Upgrade Program. Early phases of this effort gave the B-1B the ability to carry a
large payload of Mk 82 500-lb or Mk 84 1,000-lb unguided bombs, cluster munitions, and the GPS-guided
GBU-31 JDAM. Later upgrades have further added compatibility with the latest generation of precision
guided weapons such as the Wind-Corrected Munitions Dispenser (WCMD), Joint Standoff Weapon (JSOW), and
Joint Air-to-Surface Standoff Missile (JASSM).

A total of 100 examples of the B-1B were originally built, but about a third of the fleet was retired in
2003 as a cost-saving measure. By 2004, 67 aircraft were in service with the Air Force while those
operated by the Air National Guard had been retired. The remaining fleet continues to receive upgrades
to improve reliability including new avionics, radar enhancements, communications system updates to support
data links, cockpit modifications, and integration of a targeting pod. The upgraded B-1B fleet will
probably continue in service until around 2025.

originally up to 38 AGM-69 SRAM or 22 AGM-86 ALCM [no longer permitted under START]
up to 12 AGM-154 JSOW, up to 24 AGM-158 JASSM

Bomb

originally up to 26 B28/B43 or 24 B61/B83 nuclear bombs [no longer permitted under START],
up to 84 Mk 82 GP, up to 24 Mk 84 GP, up to 24 GBU-31 JDAM, up to 30 CBU-87/89/97 cluster, up to 30
CBU-103/104/105 WCMD

Other

up to 84 Mk 36 or Mk 62 500-lb sea mines, up to 8 Mk 85 sea mines

KNOWN VARIANTS:

B-1A

Original bomber design with less-refined aerodynamics but capable of Mach 2 at altitude, was cancelled in
1977 in favor of rearming the B-52 with cruise missiles; 4 prototypes built

B-1B

Production model with an improved shape for greater stealth and better flight performance at low altitudes
while sacrificing the higher speeds of the B-1A; 100 built

B-1B CMUP

Conventional Mission Upgrade Program to modernize the B-1B fleet and consisting of several Block upgrades

Boeing proposal to rebuild the existing B-1B fleet as a "regional" fighter bomber force by replacing the
F101 engines with the F119 turbofan used in the F-22 to increase speed to
Mach 2.2 but at the cost of reduced range, the rebuilt bomber would carry an AESA radar for improved
targeting and would serve as a "truck" carrying a large payload of bombs, air-to-ground missiles, and
air-to-air missiles